FreeBSD: Fix out of bounds read in zfs_ioctl_ozfs_to_legacy()

There is an off by 1 error in the check. Fortunately, this function does
not appear to be used in kernel space, despite being compiled as part of
the kernel module.

This was reported by FreeBSD's coverity scan.

Reported-by: Coverity (CID 1432059)
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>

module/os/freebsd/zfs/zfs_ioctl_compat.c

@@ -319,7 +319,7 @@ zfs_ioctl_legacy_to_ozfs(int request)
 int
 zfs_ioctl_ozfs_to_legacy(int request)
 {
-	if (request > ZFS_IOC_LAST)
+	if (request >= ZFS_IOC_LAST)
 		return (-1);
 
 	if (request > ZFS_IOC_PLATFORM) {